1. Field of the Invention
The present invention relates to improvements in the construction and manufacture of polymeric bags. In particular, the present invention relates to improvements in the construction and manufacture of elastic drawstrings for use with polymeric bags.
2. Description of the Related Art
Polymeric bags are ubiquitous in modern society. Polymeric bags are available in different combinations of material, capacity, thickness, dimensions and color. In terms of potential applications, polymeric bags may be used for product packaging, long-term storage of goods, food storage, and trash collection, among other uses. In response to consumer demand, manufacturers of polymeric bags have developed innovative, new technology over the years to improve the utility and performance of polymeric bags. The present invention described herein is one such improvement and is of particular relevance to drawstring trash bags.
Drawstring trash bags are a popular alternative to the standard twist-tie or flapped trash bags. As the name suggests, drawstring bags incorporate drawstrings, also known as drawtape, into the bag design. In a typical drawstring trash bag known in the prior art, a pair of drawstrings are enclosed within hems running along the opening of the trash bag. The drawstrings are allowed to slide freely within the hems and are physically joined to the bag by a pair of short seals formed by applying a combination of heat and pressure, welding the drawstrings to the panels of the bag. The short seals serve to hold the respective ends of the drawstrings in place, allowing a user to pull the drawstrings through the opening cut outs of the respective hems. The drawstrings can then be tied to securely close the bag and provide a convenient handle for carrying the bag.
Despite the popularity of drawstring bags, traditional drawstring bags do suffer from some disadvantages. In particular, many consumers find that drawstring bags are difficult to secure over the upper lip of a trash receptacle. For example, when the traditional drawstring trash bag is pulled over the upper lip of the receptacle, the bag does not offer any means to secure the bag to the outside of the receptacle. Therefore, when trash is placed in the receptacle, the force on the bag as the trash is thrown into the receptacle and the total weight of the trash has a tendency to pull the sides of the bag down into the trash can. It would be desirable to offer an alternative to traditional drawstring trash bags known in the art so as to provide a means for securing the bag over the upper lip of the trash receptacle.
In the prior art, it was disclosed to utilize elastomeric materials as components of the drawstrings for a trash bag to provide a way to secure the bag over the upper lip of a trash receptacle. In particular, certain prior art applications disclose an elastic drawstring trash bag with a pair of large notches at the upper corners of the bag to allow the ends of the drawstrings to be pulled through the hems along the upper corners of the bag. However, the drawstrings for these types of applications are known to be markedly thicker than ordinary drawstrings, requiring significantly more material, which, in turn, considerably increases the costs. It would be desirable to provide an elastic drawstring for trash bags that is more cost-effective.
Ultimately, the design of a quality elastic drawstring must provide a balance between minimizing the cost of the materials, retaining a sufficiently high tensile strength, and providing an elastic drawstring with suitable recovery. To minimize the cost, it would be desirable to reduce the thickness of the elastic drawstring. Similarly, utilizing traditional polyethylene rather than specialty elastomeric materials, can also reduce the cost of the elastic drawstring. High tensile strength should be balanced with a high recovery. Ideally, the drawstring would expand with a relatively high recovery but still offer a high tensile strength to prevent the drawstring from yielding when pulled to close the bag and for carrying. The present invention is intended to address these issues and desires.